Lignans from bark of Fraxinus mandshurica var. japonica and F. japonica.

Abstract
Three new lignans, (+)-fraxiresinol [(1S, 2R, 5R, 6S)-1-hydroxy-2-(3,5-dimethoxy-4-hydroxyphenyl)-6-(4-hydroxy-3-methoxyphenyl)-3,7-dioxabicyclo[3,30]octane], (+)-1-hydroxysyringaresinol and (+)-1-hydroxypinoresinol-4''-.beta.-D-glucoside, and 5 known lignans, (+)-pinoresinol, (+)-1-hydroxypinoresinol, (-)-olivil, (+)-cyclo-olivil and (+)-pinoresinol-.beta.-D-glucoside, were isolated from the bark of F. mandshurica var. japonica and the bark of F. japonica (Oleaceae). Their structures were elucidated on the basis of spectroscopic analysis and chemical evidence.